The defending champions were Dinamo Zagreb, having won their fifteenth title the previous year by defeating Hajduk Split in the final.
The following 48 teams qualified for the competition: The draw for the preliminary single-legged round was held on 1 August 2018 and the matches were played on 29 August 2018.
The draw for the first round was held on 31 August 2018 and the matches were played on 26 September 2018.
The second round matches were played on 31 October 2018.
The final was played on 22 May 2019 at Stadion Aldo Drosina in Pula.